Wireless power transmission systems include a wireless power transmission device for wirelessly transmitting electrical energy and a wireless power reception device for receiving electrical energy from the wireless power transmission device.
By using a wireless power transmission system, a battery of a mobile phone can be charged, for example, merely by placing the mobile phone on a charging pad without connecting the mobile phone to a separate charging connector.
A method of wirelessly transmitting electrical energy can be classified into a magnetic induction method, a magnetic resonance method, and an electromagnetic wave method according to the principle of transferring electrical energy.
A magnetic induction method is a method of transmitting electrical energy using a phenomenon wherein electricity is induced between a transmitter coil and a receiver coil.
A magnetic resonance method is a method of generating a magnetic field oscillating at a resonance frequency in a transmitter coil and intensively transmitting energy to a receiver coil designed to operate at the same resonance frequency.
An electromagnetic wave or microwave method is a method wherein an electromagnetic wave generated in a transmitter is received by a receiver using several rectennas and the received electromagnetic wave is converted into electrical energy.
Meanwhile, wireless power transmission can be classified into flexibly coupled wireless power transfer technology (hereinafter referred to as “flexibly coupled technology”) and tightly coupled wireless power transfer technology (hereinafter referred to as “tightly coupled technology′”) according to the magnetic resonant coupling form or strength of a transmitter coil and a receiver coil.
Here, in the case of the “flexibly coupled technology,” magnetic resonant coupling may be formed between one transmitter resonator and a plurality of receiver resonators, whereby multiple concurrent charging may be possible.
Here, the “tightly coupled technology” merely enables power transmission between one transmitter coil and one receiver coil (one-to-one power transmission).
Wireless power transmission systems can be applied to complex wireless channel environments such as homes, offices, airports, and trains.
In addition, wireless power transmission systems can be applied to an environment in which a wireless device/IoT device/wearable device is charged by synthesizing a three-dimensional beam pattern of an array antenna based on beacon positioning technology, etc. in a three-dimensional space.